Small Animal Review

The onset of seizure activity in dogs with idiopathic epilepsy is thought of as a random event, with potential trigger factors often quoted. Human epileptics report that seizure activity is unpredictable, although apparent non-random and predictable circadian rhythms, multiday rhythms and weekly, monthly, 5-weekly, 3½ monthly and annual seizure periodicities have been described in human epileptics. However, there is an absence of data on the impact medication has on seizure periodicities, both in humans and dogs. When treating epileptics, it is best practice to adjust medication in response to continued seizures, but the impact of medication changes on seizure dynamics is unknown. There is also a need to deal with seizure clusters, the dynamics of which are unclear; they may arise as a result of an inherent self-triggering capacity in which one seizure promotes subsequent seizures, or seizure clusters may reflect variation in seizure risk, in which seizures recur in high-risk phases.